Perceptual Identification and Acoustic Measures of the Resonant Voice Based on “Lessac''s Y-Buzz”—A Preliminary Study With Actors

This study aimed to verify whether the resonant voice based on Lessac's Y-Buzz can be perceived by listeners as resonant and different from habitual voice and to compare them to determine whether this sound exploration improves the vocal production. Nine newly graduated actors, six men and three women without voice complaints, were the subjects. They received a session of Lessac's Y-Buzz training from the primary investigator. Before training, they were asked to sustain the vowel /i/ at comfortable frequency and habitual loudness. After training, they were requested to sustain the Y-Buzz they had learned at a comfortable frequency and habitual loudness. Three speech-language pathologists (SLP) trained in voice developed an auditory-perceptive analysis. The pre- and posttraining voice samples were randomly spliced together, edited, and presented in pairs to perceptual judges who were asked to identify the most resonant of the pair. The voice samples were also acoustically compared through the Hoarseness Diagram and acoustic measures using the VoxMetria Software (CTS, version 2.0s, Brazil). The Y-Buzz trials were identified as resonant voice in 74% of the comparisons. The acoustic measures showed a statistically significant decrease of irregularity (P = 0.002) and shimmer (P = 0.38). The Hoarseness Diagram demonstrated how the resonant voice moved toward the normality for irregularity and noise components. The results showed that the resonant voice based on the Y-Buzz can be identified as resonant and different from normal voicing in the same subject, and it apparently implies a better vocal production demonstrating a significant decrease of shimmer and irregularity through the Hoarseness Diagram evaluation.     

Development of an Auditory-Perceptual Rating Instrument for the Operatic Singing Voice

Although considerable progress has been made in the development of acoustic and physiological measures of operatic singing voice, there is still no widely accepted objective tool for the evaluation of its multidimensional features. Auditory-perceptual evaluation, therefore, remains an important evaluation method for singing pedagogues, voice scientists, and clinicians who work with opera singers. Few investigators, however, have attempted to develop standard auditory-perceptual tools for evaluation of the operatic voice. This study aimed to pilot test a new auditory-perceptual rating instrument for operatic singing voice. Nine expert teachers of operatic singing used the instrument to rate the singing voices of 21 professional opera chorus artists from a national opera company. The findings showed that the instrument has good face validity, that it can be legitimately treated as a psychometrically sound scale, and that raters can use the scale consistently, both between and within judges. This new instrument, therefore, has the potential to allow opera singers, their teachers, voice care clinicians, and researchers to evaluate the important auditory-perceptual features of operatic voice quality.     

Effects of stimulation techniques on vocal responses: Implications for assessment and treatment

During voice evaluation and treatment it is customary for clinicians to elicit samples of the vowel /a/ from clients using various elicitation techniques. The purpose of this study was to compare the effects of four commonly used stimulation tasks on the laryngeal mechanism. Eleven female singing students, studying at a university music school, served as subjects for the study. The subjects phonated the vowel /a/ using 4 vocal stimulation techniques: yawn-sigh, gentle onset, focus, and the use of the voiceless fricative. Videoendoscopic and acoustic evaluations of their productions were done. Results show that, in the first 100 ms following the end of the formant transition, these techniques affected voice differently. The fundamental frequency was found to be highest in the yawn-sigh condition, whereas the maximum frequency perturbation was obtained for the voiceless fricative condition. Planned comparisons were made by comparing the data across 2 dimensions: (1) vowels elicited with voiced contexts versus those elicited with voiceless consonantal contexts and (2) vowels elicited with obstruent versus vowels elicited with nonobstruent consonantal contexts. Some changes in acoustic parameters brought about by these stimulation techniques may be explained on the basis of coarticulatory effects of the consonantal context.     

The effect of topical anesthesia on vocal fold motion

The objective of this study was to determine if topical anesthesia to the larynx and pharynx affects vocal fold motion during dynamic voice evaluation with transnasal flexible endoscopy. Transnasal dynamic laryngeal examinations of 10 patients with no voice complaints were evaluated by five blinded fellowship-trained laryngologists. Each patient was examined before and after application of topical anesthetic. Reviewers rated briskness of right and left vocal fold movement and longitudinal tension on a visual analogue scale. Statistical comparisons were made between individual subject scores before and after anesthetic application. Inter-rater reliability was also assessed. No statistical difference was observed between subject scores before and after anesthetic application. Average intraclass correlation coefficients were 0.643 and 0.591 for pre- and postanesthesia scores, respectively. Application of topical anesthesia to the larynx and pharynx does not affect vocal fold motion.     

Spectrographic voice identification: a forensic survey

A survey of 2000 voice identification comparisons made by Federal Bureau of Investigation (FBI) examiners was used to determine the observed error rate of the spectrographic voice identification technique under actual forensic conditions. The qualifications of the examiners and the comparison procedures are set forth. The survey revealed that decisions were made in 34.8% of the comparisons with a 0.31% false identification error rate and a 0.53% false elimination error rate. These error rates are expected to represent the minimum error rates under actual forensic conditions.     

The Towne-Heuer reading passage—A reliable aid to the evaluation of voice

The science of voice evaluation and assessment has profited from technological advancement and objective measurement of voice parameters has become an integral part of the voice examination, however, subjective voice evaluation remains a vital component of any voice examination. The Towne-Heuer Reading Passage was developed in 1970 to provide a reading sample that would facilitate subjective voice evaluation. The reliability of the passage was established using three judges listening to 15 normal Philadelphia speakers and 15 vocal abuse-misuse clients with verified vocal nodules. The frequency of hard glottal attack (HGA) was determined for the two groups and high interjudge and intrajudge correlation was found. A difference in the frequency of HGA was found between the two groups.     

The Towne-Heuer Reading Passage--a reliable aid to the evaluation of voice.

The science of voice evaluation and assessment has profited from technological advancement and objective measurement of voice parameters has become an integral part of the voice examination, however, subjective voice evaluation remains a vital component of any voice examination. The Towne-Heuer Reading Passage was developed in 1970 to provide a reading sample that would facilitate subjective voice evaluation. The reliability of the passage was established using three judges listening to 15 normal Philadelphia speakers and 15 vocal abuse-misuse clients with verified vocal nodules. The frequency of hard glottal attack (HGA) was determined for the two groups and high interjudge and intrajudge correlation was found. A difference in the frequency of HGA was found between the two groups.     

Nasalance Changes After Functional Endoscopic Sinus Surgery

Forty adult patients diagnosed with chronic rhinosinusitis who underwent functional endoscopic sinus surgery (FESS), were analyzed with respect to postoperative resonatory voice changes. For evaluation the patients were asked about their subjective impression of voice changes using a questionnaire. An objective assessment was performed by determining the so-called nasalance using the Nasometer (Kay Elemetrics), preoperatively, on the immediate postoperative follow-up (2 days after surgery), and approximately 1 month after surgery. The mean nasalance values increased significantly one month after FESS whereas the immediate postoperative control (2 days after surgery) showed a decrease of nasalance. Although FESS is a minimally invasive procedure, it can change the acoustic characteristics of the vocal tract in the long term and produce a significant increase in nasality. The authors strongly recommend that clinicians inform all patients, in particular voice professionals, about the possible effects of endonasal sinus surgery on voice quality.     

Documentation of progress in voice therapy: perceptual, acoustic, and laryngostroboscopic findings pretherapy and posttherapy

The effect of voice therapy in a group of chronically dysphonic patients with diverse diagnoses was studied according to the normal clinical procedure. The results were evaluated by perceptual rating, acoustic analysis, and the assessment of laryngostroboscopic recordings. Although the group effects for the differences between posttherapy and pretherapy data were clearly significant, the effects of voice therapy for the individual patients were divergent. For each of the three evaluation methods, a significant improvement was found for about 40% to 50% of the patients. The diversity of the therapy outcome among the patients could not be explained by the pretherapy status nor by age, gender, or diagnosis groups. In general, the perceptual ratings and the acoustic parameters from the baseline data were clearly correlated. However, these characterizations of the voice were only moderately correlated with the visual evaluation of the vocal fold vibrations. Relations among the three evaluation tools for the changes caused by voice therapy were very weak. The low correlation among the three methods suggests that a multidimensional evaluation of the voice is necessary to give a complete picture of the therapy outcome.     

The Effectiveness of Group Therapy for Students With Mild Voice Disorders: A Controlled Clinical Trial

Previous studies of students studying to be teachers have indicated that these students commonly have voice disorders. Ideally, voice disorders should be treated before students start their work as teachers, but the resources for this treatment are often limited. This study examines whether group voice therapy is effective for teacher students. Accordingly, 20 teacher students with mild voice disorders received group voice therapy (in three small groups), whereas 20 students with similar voice disorders served as a control group and consequently did not receive voice therapy. Two out of three outcome measures (perceptual evaluation of voice quality and a questionnaire on the occurrence of vocal symptoms) indicated significant changes in the treatment group compared with the control group. No differences between groups were noted in the laryngeal status. The results suggest that group voice therapy seems to be an effective method to treat students with mild voice disorders.     

Intensive voice treatment in parkinson disease: Laryngostroboscopic findings

As part of ongoing research to investigate and document the efficacy of intensive voice therapy to improve functional communication in patients with idiopathic Parkinson disease, 45 patients were enrolled in a controlled, randomized, prospective study. Pre- to posttreatment comparisons are presented here on 22 of those patients who underwent laryngeal imaging examination. Of the 22 patients, 13 patients received intensive therapy aimed at increasing vocal and respiratory effort (VR), whereas nine received intensive therapy aimed at increasing respiratory effort (R) only. All patients had a pretreatment evaluation that included two (but sometimes only one) voice recordings and an otolaryngologic examination with laryngostroboscopy. At the completion of 4 weeks of therapy (16 sessions), two voice recordings were made, and laryngostroboscopy was again performed. The pre- and posttherapy videolaryngostroboscopy tapes were then randomized and rated by four judges. Raters' findings were then compared with vocal intensity measured before and after therapy. The VR therapy group showed improvements on laryngostroboscopic variables: less glottal incompetence and no significant change in supraglottal hyperfunction after therapy. No differences were observed in the R-only group. The mean intensity increase in the VR therapy group was 12.5 dB, compared with a decrease of 1.9 dB in the R-only group. These findings suggest that in patients with Parkinson disease, intensive therapy focusing on phonatory effort improves adduction of the vocal folds as assessed by laryngostroboscopy. Differences in laryngeal function in these patients observed with fiberoptic laryngoscopy and rigid telescopic laryngoscopy are discussed.     

What's so special about singers?

Research on singers' breathing, phonation and articulation patterns during singing is reviewed and comparisons are made with typical speech patterns. It is found that singers' and nonsingers' use of the voice differ in several respects. The reasons for these differences are discussed and explanations are proposed referring to the special demands raised on singers with respect to economization of vocal effort and flexibility of phonation.     

Voice handicap index change following treatment of voice disorders

Outcome measurements of voice disorders is an important new area for both the evaluation of voice-disordered patients and evaluation of treatment efficacy. The Voice Handicap Index (VHI) measures the patient's perception of the impact of his or her voice-disorder. The VHI was used in this study to measure the changes of the patient's perception following treatment for four different voice disorders. The VHI showed a significant change following treatment for unilateral vocal fold paralysis, vocal cyst/polyp, and muscle tension dysphonia. Results of this paper indicate that the VHI is a useful instrument to monitor the treatment efficacy for voice disorders.     

Validation of an instrument to measure voice-related quality of life (V-RQOL)

When a patient presents for care of a voice disorder, the clinician attempts to diagnose the problem, quantify the degree of dysphonia, and prescribe appropriate treatment. Quantification of the degree of dysphonia is often difficult, as no universal index of vocal function exists. Decisions about the nature and intensity of treatment are often based on the magnitude of the voice-related problems experienced by the patient and the importance that the patient places on those problems, that is, the impact that the voice disorder is having on the patient's voice-related quality of life (V-RQOL). Measurement of post-treatment outcome is also not standardized. Regardless of how the clinician measures response to treatment, it will typically be measured by the patient in terms of how his or her voice-related problems are affected by the treatment.

Measurement of quality of life has not been a traditional part of the evaluation of the dysphonic patient. This study was undertaken to develop and validate an instrument for measuring V-RQOL using a population of 109 voice and 22 non-voice patients. The 10-item V-RQOL measure performs well in tests of reliability, validity, and responsiveness, and it carries a low burden. Measurement of V-RQOL is a valuable addition to the evaluation of dysphonic patients and their treatment outcomes.     

Musculoskeletal Patterns in Patients With Voice Disorders

This study correlated the ear, nose, and throat (ENT) and physiotherapy input on 26 patients who presented with voice problems and were found by the ENT surgeon to have a degree of musculoskeletal issues. It also looked for patterns of musculoskeletal findings. Although all patients referred were found by the physiotherapist to have musculoskeletal abnormalities, the correlation proved to be excellent among the subgroup of performers, but only fair-to-good among the other voice professionals. Certain patterns of musculoskeletal abnormalities were frequently encountered, including a high held larynx, a shortening or contraction of the stylohyoid and sternocleidomastoid muscles, and a weak deep flexor mechanism. In this small group, most patients seemed to improve, although it must be noted that management was not limited to physiotherapy. In summary, physiotherapy input proved helpful in the evaluation and management of this group of patients presenting with voice problems.     

Voice and Lifestyle Behaviors of Speech-Language Pathology Students: Impact of History Gathering Method on Self-Reported Data

ObjectivesThis study described voice use and lifestyle information from student speech-language pathologists (SLP) and assessed the impact of history gathering method on the acquired data.MethodsOne hundred sixty-two SLP students completed a detailed history form and estimated voice and life style parameters at study intake and subsequently tracked the same parameters daily for three consecutive weeks. Nonparametric statistical comparisons were applied to assess differences in estimates at intake versus the 3-week log.ResultsVoice problems diagnosed by a physician or SLP were reported by 11% of the students. A similar percentage reported frequent loud talking and heavy occupational voice demands beyond clinical training use. Furthermore, high stress was reported by 49%, frequent anxiety by 53%, and depression by 17%. Comparing data from study intake relative to the 3-week log, SLP students statistically significantly overestimated speaking time, and underestimated singing, second hand smoke exposure time, and hours of sleep. Additionally, they overestimated water intake and daily stress, and underestimated caffeine and alcohol intake, at the study onset versus the log. The experience of vocal fatigue was common within the 3-week log, but how a student identified at study intake on this parameter (experiencing it frequently or not) did not differentiate how many days of vocal fatigue were reported in 3 weeks.ConclusionsSLP students engage in some voice use and lifestyle behaviors that place them at risk for voice problems. The method of soliciting information about the voice and lifestyle of SLP students impacted the information obtained. Optimal methods of gathering accurate and reliable clinical history and voice us data are needed.     

Strobovideolaryngoscopy in professional voice users: Results and clinical value

Evaluation of the vibratory margin of the vocal fold is essential for accurate diagnosis and treatment of voice patients. Traditionally, physicians have performed this evaluation using their subjective impressions of the sound of the voice in conjunction with laryngoscopy under continuous light. Strobovideolaryngoscopy is a valuable addition to the diagnostic armementarium. It allows the physician to perform a proper physical examination of the vibratory margin. A review of 486 strobovideolaryngoscopy procedures in 343 voice patients during a 2-year period reveals that stroboscopic information influenced diagnosis or treatment in approximately one-third of the entities diagnosed.     

Repetitive Phonatory Tasks for Identifying Vocal Fold Paresis

Vocal fold paresis may be present in patients with voice complaints. Identification of paresis is important so that appropriate neurolaryngologic evaluation can be ordered and the appropriate treatment can be offered. Repetitive phonatory tasks (RPTs) fatigue patients vocally and may elicit signs of subtle paresis. In this study, four laryngologists independently reviewed the RPT portions of routine fiberoptic voice examinations of 100 patients in a blinded fashion. All patients had presented with voice complaints, were suspected of having a movement disorder of the larynx, and had been referred for laryngeal electromyography (LEMG). Predictions were compared with LEMG results and with predictions made at the time of each initial evaluation. Although RPTs are useful to laryngologists, predictions based on the entire examination are more accurate. LEMG can confirm clinical suspicions or identify paresis missed on fiberoptic laryngeal examination.     

Investigation of the Effectiveness of a Holistic Vocal Training Program Designed to Preserve Theatre Students’ Vocal Health and Increase Their Vocal Performances; A Prospective Research Study

ObjectiveThe main purpose of this study is to investigate the effectiveness of a 12-week holistic vocal training program designed for theatre students.MethodsThe participants included 10 female and 8 male students, who were third- and fourth-year students of a state conservatory theatre department. Participants randomly selected from among those who were between the ages of 18–30 years, had no history of voice disorders, and had no systemic and neurological disorders. The study group (n = 9) was involved in the vocal training program. The control group (n = 9) has not received any training. During the program, 12 sessions of lectures and voice exercises were given to all participants of the study group for a period of 12 weeks. The sessions were planned to last for a duration of 30–45 minutes. Participants’ knowledge of vocal health was assessed using a questionnaire that was developed in the present study and a multidimensional voice assessment protocol including acoustic analyses and audio-perceptual evaluation has been applied.ResultsWithin-group comparisons indicated a significant increase in the study group participants’ knowledge of vocal hygiene after training (P = 0.011). Similarly, the study group outperformed the control group in the vocal mechanism knowledge (P = 0.027). Multidimensional Voice Profile findings revealed that vocal qualities of the control group deteriorated, whereas no alterations were found in the study group. Audio-perceptual analysis conducted through the Consensus Auditory-Perceptual Evaluation of Voice did not introduce significant changes in the control group in overall severity and roughness parameters, these values were found significantly improved for the study group.ConclusionIt can be concluded that the Holistic Vocal Training Program designed in the present study is effective for preserving theatre students’ vocal health and voice quality. It is important for future studies to search the long-term effects.     

Direct magnitude estimation and interval scaling of pleasantness and severity in dysphonic and normal speakers

The purpose of this study was to determine the validity of voice pleasantness and overall voice severity ratings of dysphonic and normal speakers using direct magnitude estimation (DME) and equal-appearing interval (EAI) auditory-perceptual scaling procedures. Twelve naive listeners perceptually evaluated voice pleasantness and severity from connected speech samples produced by 24 adult dysphonic speakers and 6 normal adult speakers. A statistical comparison of the two auditory-perceptual scales yielded a linear relationship representative of a metathetic continuum for voice pleasantness. A statistical relationship that is consistent with a prothetic continuum was revealed for ratings of voice severity. These data provide support for the use of either DME or EAI scales when making auditory-perceptual judgments of pleasantness, but only DME scales when judging overall voice severity for dysphonic speakers. These results suggest further psychophysical study of perceptual dimensions of voice and speech must be undertaken in order to avoid the inappropriate and invalid use of EAI scales used in the auditory-perceptual evaluation of the normal and dysphonic voice.